Sound record and method of making the same



Patented Mar. 1, 1932 ram a. new, or YORK, II. Y.

som man u men or name m sum 80 Drawing.

The present invention relates to sound records and methods of making the same and is more particularly directed toward a ma etized sound record wherein the magnetized 8 material is incapable of self support when in use but is upported and carried on a base. I

The present invention contemplates sound records wherein the sound is recorded mag- 10 netically in magnetizable material supported on a base, either flexible such as a film, or

' rigid such as a record blank, of the type employed for phonograph records. Sound records, of the type to which the present inven- 1 .tion is directed, are adapted to provide means for reproducing sound and voice for simple voice reproduction, for talking moving pictures, or for makin records for sound reproduction for ta ing moving pictures so ada ted to be transmitted by; television.

The present invention a o contemplates the making of a master magnetic record from which any number of positive reproductions may be made. These reproductions may be made on the same or different base, and, when made on a film which carries pictures, the sound record is electromagnetically produced on the film simultaneously with the pictures.

The present invention also contemplates providing an electromagnetic sound record on a film or other supporting base and wherein the magnetized or magnetizable material is protected by a thin metallic coating. This metallic coating may, according to certain features of the invention, be produced simultaneously with the printing and development of the picture and may employ the reduced metal which is produced when the film is exposed and developed.

While various magnetizable materials may be employed, I prefer to use iron on account of its superior magnetic properties. The iron or other magnetizable material is produced in colloidal form and is incorporated in a suitable binder. This binder and iron are placed on the surface of the film or rec-.

0rd blank in any convenient manner, such for example as by a spraying process. Where a film is used, a stationary sprayer may be Application Med January 28, 1989. Serial No. 884,610.

employed and the film assed by the nozzle of the sprayer so that t e binder and ma netlzable material may be spread along m a streak or strip adjacent the edge of the film. The surface of the film is then treated in the ordinary manner to produce an unexposed photographic film, the emulsion extendlng over and covering the magnetizable coating.

Where the sound record is to be used with a rigid blank such as a phonograph record blan the entire surface of the blank is coated with the magnetizable iron and binder preparation, and then a light sensitive emulsion may be placed on top of the binder.

To produce a sound record, an unexposed base with the binder and photographic covering is exposed to the influence of an electromagnetic sound record device which is energized by currents corresponding with the sound and voice which it is desired to be recorded. The film may be moved so as tobe under the influence of the electromagnetic recording devices.

Where the record is to be made on a film which also is to carry a picture, the sound recording device is suitably synchronized with the moving picture camera mechanism so that the sound record may be impressed on the moving film before or after it has been exposed. The devices employed for s chroniz-ing the sound and picture recording may be of the same general type as those now available for synchronizing picture taking and sound recording where the sound record 85 is produced on the film, as for example, by the efl'ect of light on the emulsion. After the record has thus been exposed, it is developed by the usual photographic processes of developin the negative of the motion picture film. T e art of the film which carries the sound recor only is exposed to light so that the silver is reduced to the metallic state thereby providing metal coating on top of the sound record bearing coating. This metal coatin forms a protection for the magnetized coating and at the same time is nonmagnetic and has no effect upon the magnectic pro erties of the structure.

When t e base is in the form of a record blank, it is revolved in the usual manner of revolving phonograph records of either disk or cylinder form. In the case of these rigid blanks, mechanical devices are provided for feeding the electromagnetic recorder in a spiral so that the entire surface of the blank may be magnetized.

In the above manner one produces a master record. Other records may be obtained from the master record by passing it through an electromagnetic reproducing device which will be energized according to the magnetic record im re'ssion in the coating. The currents pro need in this reproducing device may be amplified and passed through a recording device which acts on another similar film or on another base having an unmagnetized coating. The production of the duplicate sound records may be made either on the same type of base as the original sound record was impressed upon, or may be made on another ty e of base. For example, the original sound record might have been taken on a film alonv with the moving picture and the reproduced record recorded on a synchronized record blank.

When the copy is made on a film, 1t may be at the same time that the positive film is being printed in the moving picture printing apparatus whereby the sound prlnt and picture print are made simultaneously. It is not, however, entirely necessary that the sound record be impressed on the film simultaneously as the making of the phonograph record for the magnetic recording device may be employed on the film after the photographic developing process has been completed. The iron particles are magnetized underneath the silver coating in the same manner that they are magnetized before photographic printing.

It will be noted from the foregoing that the method is susceptible of wide variation in that the sound recording may be made before or after the photographic print and that the magnetic recording device may operate simultaneously with the printing mechanism, or not, as desired. In either case, the film is developed and dried and the sound record portion of the film requires no special processes in the photographic treatment of the film. The silver coating on top of the voice record coating covers the voice record and prevents dissolving out the binder during the developing processes.

It will be understood that the reproduc tion of the sound and its amplification will be accomplished in substantially the same manner as though the magnetic recording were on a wire or other rigid magnetizable object. Sound records made according to the present. invention have remarkable advantages in that the sound record is readily produced on a standard film treated to carry the magnetizable material before treated f r photographic purposes. The sound record emplo s but a very narrow strip of the film and t e advantages of electromagnetic re cording are available without making it necessary to employ wires and other devices for carrying the sound record. Furthermore, inasmuch as the colloidal iron or other m netizable material is in the state of extreme y minute subdivision, there is a minimum tendency for the ma netized record to de-mag- .netize itself as in t e case in magnetized wires and the like on which sound records have been impressed magnetically.

It will of course be understood that when the magnetic record is on a rigid blank such as a honograph blank, that the reproducer will moved over the record so as to ick up the sound in the same sequence in w ich it was recorded.

What is claimed is:

1. A sound record comprising a supporting base having a coating of colloidal magnetizable particles.

2. A sound record comprising a sup rting base and a magnetiza le coating oFdolloidal iron.

3. A sound record comprising a magnetizable medium incapable of self support, and a supporting base of non-magnetic material.

4. A sound record comprising a magnetizable medium in the form of particles of colloidal iron dispersed in a binder and incapable of self support, and a supporting base of non-magnetic material.

5. A sound record comprisin base, a magnetizable coating of and a protective coating.

6. A sound record comprising a supporting base in the form of a transparent film, a magnetizable coating of colloidal iron over a portion of the film, and a light sensitive coating on the film and on to of the iron coating whereby pictures may be reproduced on the film and a protective metallic coating may be produced on the magnetizable coating by ex osure ofthe film and developin the same.

A magnetizable sound recor comprising particles of colloidal iron dispersed in a binder and forming therewith a coating on a non-magnetic base.

8. A magnetizable sound record comprising particles of colloidal iron dispersed in a inder and forming therewith a coating on a non-magnetic base, and an insoluble coating on the first coating.

9. The step in the method of making a sound record which consists in applying to a supporting base, a coatin of magnetizable colloidal particles in a bin er.

10. The method of making a sound record which consists in applying to a sup orting base, a coating of magnetizable colloidhl particles in a binder, and passing the coated base past a magnetizing device to im ress a magetic condition on the individua particles.

a su rting colloi a1 iron 11. The method of making a sound record which consists in applying to a sup rting base, a coating of magnetizable collo1 al particles in a binder, covering the binder with a light sensitive material, and developing the light sensitive material to produce a metallic coating for the magnetizable coating, and magnetizing the magnetizable particles.

FRANK M. BEST. 

